SLATE INDUSTRY — the industry occupied with production and processing of slate.
Slates (combustible) consist from organic (15 — 35%) and mineral (65 — 85%) parts; slates are a kind of solid hydrocarbon fuel, a cut is used for power needs and as a feed stock for chemical processing. At thermal decomposition slates allocate up to 30% of pitch and 320 — 350 m3/t of high-calorific household gas.
The page of the item includes slate production and a slantsepererabotka. The Slantsedobycha is made by underground developments (mine) or an open way (cuts). Working conditions in slate mines are characterized by preferential low air temperature (apprx. 9 °), high relative humidity (to 98%), dust content of the air environment (see. Dust ) in the concentration which are quite often exceeding maximum allowable concentration; work of navalootboyshchik (stope miners) is accompanied by big physical tension, drillers — by a forced uncomfortable position of a body, action noise (see) and vibrations (see), blasters — with tension of attention and danger of poisoning with explosive gases. Workers-drifters are affected by slate dust and the noise published by porodopogruzochny cars. Land works in nonmechanized mines are connected with a manual porodovy-borka, require the physical tension and constant attention. In the mechanized mines weight of physical work, dust content of air are less expressed, but bigger value gets action of vibration and noise.
On cuts at an open way of extraction of slate of a working condition are characterized intensive a heat - and the gas-allocations happening during the drilling-and-blasting and handling works, pollutions of soot (during the operation of diesel engines) and exhaust gases (during the operation of cars and tractors).
Long work in the conditions of the increased concentration of slate dust can lead to development pneumoconiosis (see), to-ry it is characterized by an intersticial form of a pneumosclerosis and slow development of a disease; the combined effect of dust and explosive gases — to development hron. bronchitis (see). At the miners working with an electrodrill, at non-compliance established a gigabyte. rules of work development of a peculiar form of a vibration disease is possible (see), at a cut the expressed generalization of vascular disorders is not observed and seldom changes of muscles and c come to light. N of page. A frequent disease is lumbosacral radiculitis (see). At the workers occupied on sites of sortings and enrichment factories, relative deafness — the main professional pathology.
A main type of a slantsepererabot-ka is thermal decomposition of slate therefore receive slate pitches and household gas. Slate pitches — the complex multi-component mixtures containing from 17,4 to 28% of phenols. On their basis fuel and shpalopropitochny oils are produced, benzene (see), toluene (see), phenol-formaldehyde resins etc.
Air of a working zone on installations of a slantsepererabotka contains vapors of phenols, carbon monoxide, sulfur dioxide, hydrocarbons and slantsezolny dust (maximum allowable concentration of 4,0 mg/m3), concentration to-rykh generally do not exceed maximum allowable concentration.
Slate pitches and the majority of the products made on their basis possess the local irritative, sensibilizing and all-toxic action. Control of the air environment on sites of a slantsepererabotka is carried out on phenol (maximum allowable concentration of 0,3 mg/m3) and hydrocarbons (maximum allowable concentration of 300 mg/m3 in terms of carbon).
At the persons contacting to slate or slantsezolny dust and sour gases (loaders of generators, operators-generatorshchiki, workers of ash handling, etc.), are observed hypertrophic and atrophic rhinitises (see), hron. bronchitis. At working with slate pitches and phenols, and also the marketable products made on their basis functional disturbances central and the autonomic nervous system, an abnormal liver function, and also various damages of skin and allergic reactions are possible.
Preventive actions at extraction of slate are directed to automation and mechanization of heavy and heavy works; implementation of self-propelled boring installations and more perfect buropogruzochny cars; water delivery under a cutter of the combine and use of washing during the drilling of shots (holes); moistening of slate during the transportation, the shelter of the raising dust processes, the equipment of aspiration devices in places of formation of dust. From medical measures of prevention an important role is played by preliminary and periodic medical surveys of workers, use of individual protection equipment and use of preventive uv radiation in fotariya, to lay down. physical cultures, ae-rozolyingalyation etc. Duration of working week for the persons occupied at underground works makes 36 hours; at these works work of women and persons under 18 is prohibited; working this category the right to retire from 50 years is granted.
For improvement of working conditions during the processing of slate automation of processes of transportation, loading of slate, unloading of ashes, sealing of processing equipment, automation and mechanization of processes of a flood and casing etc. have the most essential value.
Bibliography: Blinova E. A., In e l Dr. I. A. and Yanes X. Ya. Toksikologiya of slate pitches and phenols, Tallinn, 1974; Bogovsky I. A. Cancerogenic action of products of processing of the Estonian slate, Tallinn, 196.1; Occupational health and professional pathology in the Estonian SSR, century 10 — Health protection at production and processing of oil shales, under the editorship of I. I. Akkerberg, etc., Tallinn, 1980; To yu N of V. A. Slate pneumoconiosis, Tallinn, 1959.
X. A. Kakhn.